Shaun,
I have owned 6 heng long tanks in the past when i was a lot more invested in this hobby then i am now (I switched to other hobbies that needed less storage space and expense). But IMO you might be better off with two tigers, one to customize full metal and one to drive. All those metal parts will make the tank so heavy it won't move very fast at all...and the metal tracks in particular, are seldom trouble free and tend to fall off, even when you have the running gear to match (The metal IMEX hull for instance). All-metal tracks and wheels will be heavier then the rest of the tank put together - and will require the metal replacement arms to be installed since the plastic ones, if retained, will tend to bend if not break. In short, you can make it work but you may not be satisfied with the results.
If I were you, wanted to do all this and budget was no object, I would consider getting the all-metal Tiger tank. It would still be slow, to be sure, but at least the whole tank is made to bear all those metal parts.
Mato 1/16 Scale ALL METAL German Tiger I Tank